Hidden roof conditions

Roof decking, hidden damage, and change orders

The condition of every roof-deck area may not be visible before tear-off. A good contract explains how damaged decking and other hidden conditions will be documented, priced, approved, and repaired.

DeckingHidden damageUnit pricesChange orders

Why decking may be hidden

Roof covering and underlayment can conceal rot, delamination, broken boards, old openings, inadequate fastening, moisture damage, or prior repairs. Interior or attic signs may reveal risk but cannot always define the full scope.

The proposal should state

  • What deck material and thickness are expected
  • How much replacement is included, if any
  • The unit price for sheets, boards, or measured repairs beyond the allowance
  • Who documents damaged areas and how approval is obtained
  • Whether structural framing, insulation, hazardous materials, or interior damage is excluded
  • How added work affects price, schedule, and warranty

A useful change order

A written change order should identify the condition, added or deleted scope, price effect, schedule effect, and approval. Emergency work needed to make an opened roof weather-tight should be addressed in the contract before tear-off begins.

Why this is the change order that always happens

Short answerDeck condition cannot be known until the covering is removed, so a replacement contract needs either an included allowance of replaced sheathing or a written unit price — plus how the quantity is measured and who authorises it.

Almost every genuine surprise in a roof replacement is beneath the covering. Older Chittenden County housing includes plank sheathing, prior layer-overs, patched sections, and areas softened by long-running leaks around chimneys, valleys and eaves. None of that is visible from the ground and none of it is reliably visible from a satellite measurement.

Two proposals with identical headline scope can behave completely differently here. One may include a set quantity of replacement sheathing and a unit price beyond it; another may leave it undefined and price it after the fact. Ask every bidder the same question — what happens on the day you find bad decking — and compare the answers rather than the totals.

What to pin downWhat good looks like
Included allowanceA stated quantity in sheets or square feet, included in the contract price
Unit price beyond itA written per-sheet or per-square-foot rate agreed before work starts
MeasurementHow replaced area is measured and evidenced, not estimated afterwards
AuthorisationA signed writing before extra work proceeds, as Vermont requires
EvidenceDated photographs of the exposed deck before it is covered
Non-standard conditionsHow plank sheathing, prior layers, or unusual spacing are handled and priced

What Vermont requires about changes

Short answerFor residential work estimated at $10,000 or more, the contract must describe how amendments are approved and documented, and the parties must document an amendment in a signed writing.

That is not a courtesy — it is contract content the state specifies, and it exists precisely for situations like decking. A verbal “we found some bad wood, it'll be a bit more” is not the process, and agreeing to it removes your only record of what was authorised and at what rate.

The practical version is simple: agree the unit price before the roof is opened, require a photograph and a signed change order before the extra work proceeds, and keep both with the contract. That takes ten minutes on the day and prevents the most common dispute in residential roofing.

Reading the photographs

Ask for dated photographs of the exposed deck before new material covers it, and ask for them whether or not anything was replaced. A clean deck photographed and reported is as useful as a rotten one — it is evidence that the allowance was not spent, and on a fixed allowance it should mean a credit or an unused balance rather than silence.

What you are looking for in the photographs is consistency with the invoice: the area described, in the location described, in the quantity charged. This is the single cheapest control available on a roofing project and almost nobody asks for it.

Published August 12, 2026 and last reviewed August 16, 2026 by Greater Burlington Roofing. General roofing information; an on-site inspection is required for property-specific recommendations.

Roofing FAQs

Roof decking, hidden damage, and change orders questions

What is a decking allowance?

A stated quantity of replacement sheathing included in the contract price, with a written unit price for anything beyond it. It exists because deck condition cannot be known until the roof is opened.

What is a reasonable unit price for replacing sheathing?

That is a market question your bidders should answer in writing, and comparing their rates on the same basis is more useful than any figure quoted elsewhere. What matters is that the rate is agreed before the roof is opened rather than after.

Can the contractor just replace what they find and bill me?

They should not. Vermont requires a residential contract at or above $10,000 to describe how amendments are approved and documented, and for amendments to be documented in a signed writing. Agree the process before work starts.

What if my allowance is not used up?

Ask before signing. On a fixed allowance included in the price, an unused balance should be addressed explicitly — either credited or acknowledged — rather than quietly retained. Getting that in writing avoids the question arising later.

Should I be there when they open the roof?

It helps if you can be, but photographs serve the same purpose and are more reliable. Ask for dated photographs of the exposed deck before it is covered, whether or not anything is replaced.

Is plank sheathing a problem?

It is not automatically a problem, but it changes the work — fastening, spacing, and sometimes the need for an overlay all differ from modern sheet sheathing. It should be identified and its handling priced rather than discovered as a surprise.

Does a decking allowance apply to a repair, or only a full replacement?

It matters most on a full replacement where the whole deck is exposed. A repair only opens a small area, so the equivalent question there is simply whether any decking found soft in that specific spot will be replaced and how it is priced.

Who decides how much decking actually needs replacing?

The roofing company identifies and photographs soft or deteriorated decking as it is exposed, but you or your agreed process authorize the extra cost via the signed change order — it should not be a unilateral decision by either party.

Can I negotiate the unit price for decking after signing the contract?

It should be agreed before the roof is opened, not renegotiated once bad decking is found and leverage has shifted. If the rate was not settled up front, that is a gap worth closing before work begins rather than after.

What does 'decking' actually refer to — is it the same as sheathing?

Yes, decking and sheathing are the same thing in this context: the structural panels or boards fastened to the rafters that the roofing covering is installed over.

Does newer construction ever have decking problems too?

Less often than older housing, but it can — moisture intrusion from a prior undetected leak, poor original material, or inadequate fastening can all produce soft decking on a relatively young roof, even though it is less common.

How is decking replacement typically priced — per sheet or per square foot?

Both conventions are used by different companies. What matters is that whichever unit is used, the rate is stated clearly and in writing before work begins, so the eventual invoice is a simple multiplication rather than a negotiation.

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